This is the second of four installments in VFXWorld’s The Chronicles of Narnia: The Lion, The Witch and the Wardrobe production diaries.

In January 2005, Rhythm & Hues’ focus is on finishing the significant portions of the pre-production work, including the character rigging and setup for Aslan. All images © Disney Enterprises Inc. and Walden Media Llc. All rights reserved.

I previously explored our “pre-production” phase, which involved developing and integrating the software we would need, starting character rigging and development and our responsibilities during principle photography. This part will cover everything else that brought us to final delivery at the end of October 2005.

At the point where this installment picks up, our team is all back at our studios in Los Angeles and our primary focus is on finishing up the significant portions of our pre-production still remaining. We have to finish our character rigging and setup, especially the facial rig for Aslan. We are also heavily into the motion capture and motion editing for our Massive agents and are working on the agent brains so we can start placing Massive into shots sometime in May. While this is going on, we do have our first batch of shots in-house, which are all from Aslan’s sacrifice scene at the stone table.

Jan. 16, 2005
The final touches for Aslan’s facial rig are finally being put into place. This is the culmination of work that really started last August. The challenge now, as was then, is that we still do not have a voice from production. The voice really determines a lot about a character and will inform some of the subtle specifics of our facial poses. In the meantime, we have to make do with our best assumptions. Our facial rig is a combination of a shape-based blend system with an additional layer of muscle and traditional deformers layered on top. A shape-based rig uses pre-built facial poses that an animator can select, combine and animate between. At this stage in our development, we have incorporated everything we can until we have a voice and can evaluate whether we need additional improvements.

Bill Westenhofer, vfx supervisor, Rhythm & Hues.

The process of building the face shapes started last summer by looking at the problem from two directions. The first was to consider the range of poses that a lion was anatomically capable of making. We had an entire room filled with snapshots we had collected from our reference and from the day we spent in a lion cage at Gentle Jungle. From them we found numerous examples of captured moments where a real lion happened to look angry, sad, contemplative and so on. These were useful because they were clearly anatomically possible, and thus “on-model,” and so were a great way of insuring a sense of “lioness” in the poses we built. The other way we approached the task was to find a human performer who seemed to exude what we thought of Aslan’s character. Even with a voice, finding such an example would be useful; without one, it was essential.

Our animation director, Richie Baneham, made the inspired call to propose Gregory Peck’s portrayal of Atticus Finch in To Kill A Mockingbird. Atticus’ powerful, authoritative, sublime persona seemed to fit Aslan perfectly. When Andrew agreed with our assessment, we moved forward with the idea. This allowed us to find still frames from the movie that portrayed through Atticus, a typical “Aslan angy,” “Aslan happy, “ “Aslan proud” and so on. With a mockup rig that had been formed with the lion shapes built from the previous stage, we created new poses that had the same feel as the stills of Atticus. Where necessary, adjustments to the underlying rig were made, and in the end our set of performance shapes were complete. So long as the final selection for Aslan’s voice doesn’t clash with the Atticus persona, we will be ready for shot production.

R&H found it essential to focus on a human performer who exuded Aslan’s character. Before Liam Neeson was cast as the lion, the digital team found inspiration in Gregory Peck’s portrayal of Atticus Finch in To Kill A Mockingbird.

From a technical perspective, we also did a lot of things in the building of Aslan’s facial rig that improved on issues we’d had with past rigs. We had used fully muscle driven facial setups before and know that they produce the most anatomically correct setups. They do this, however, at a cost of being awkward and complex to animate with. The alternative we chose in this case was to use a muscle system to create the blend shapes for a shape-based approach. This would make the rig much easier to work with on a shot to shot basis, while preserving all of the subtle details the muscle systems create. To further improve the process, Wil Telford, one of our creature supervisors, along with lead Aslan facial rigger, Brad Hiebert, devised an ingenious scheme of allowing modelers to free-hand sculpt rough poses in our modeling package which can be done very quickly to get the essences of the gestures. The muscle system would then look at key areas in the posses the modelers had built and determine what muscles needed to fire to achieve the shapes. If a mouth corner was moved, for example, the muscle system would propagate the necessary motion of the cheeks and jaw muscles to achieve a new shape that had complete anatomical integrity. This new shape is what would be incorporated into the final rig.